Accelerated Aging: Photochemical and Thermal Aspects

Description

The book, representing the culmination of more than forty years of research, focuses on the long-term performance of materials such as wool, dyes, and organic compounds; their resistance to change when exposed to environmental factors such as oxygen, ozone, moisture, heat, and light; and their physical durability with handling and use over time. Processes of deterioration are discussed based on speeded-up laboratory studies designed to clarify the chemical reactions involved and their physical consequences.

Table of Contents

Foreword

Preface

Acknowledgments

Objectives of Accelerated Aging

Introduction

Chapter 1 Classes of Stability

Range of Stability

Class of Stability

Statistical Approach to the Probability of Failure

Materials of Moderate or Intermediate Stability

Summary

Chapter 2 Changes with Age That Are Measured

Chemical versus Physical

Mechanism

Sensitivity of Measurement

Choosing an Acceptable and Unacceptable Degree of Change

Summary

Chapter 3 Kinetic Analysis of Change

Equations Expressing Changes in the Concentration of Reactants

“Order” of Reaction

Sequential, Simultaneous, and Reversible Reactions

How Properties Change in Time

Summary

Chapter 4 Prediction of Useful Lifetime

Empirical Equations

Change According to Laws of Chemical Kinetics

Sizmann and Frank Method

Statistical Analysis of Probability of Failure

Correlation

Controls

Summary

Chapter 5 Theoretical Aspects of Photochemical Deterioration

To Activate Molecules, Radiant Energy Must Be Absorbed

Photolysis

The Primary Process

Secondary Processes

Reciprocity Principle

Reactions Proportional to the Square Root of Intensity

General Influence of Temperature in Photochemical Reactions

Initiation

Depth of Penetration of Light into Coatings

Summary

Chapter 6 Influence of Wavelength

Activation Spectra

Effects Observed over an Extensive Range of Wavelengths

Relatively Broad Regions of Sensitivity in the Ultraviolet

Sharp Dependence on Wavelength

Depolymerization of Poly(methylmethacrylate) and Other Acrylic Polymers

About the Authors

Robert L. Feller joined the Mellon Institute (now Carnegie Mellon Research Institute) in Pittsburgh as senior fellow of the National Gallery of Art Research Project on artists’ materials. In 1976 he became director of the Center for Materials of the Artist and Conservator through a grant from the Andrew Mellon Foundation. An Honorary Member of the American Institute for Conservation, he is director emeritus of the Research Center on the Materials of the Artist and Conservator at Carnegie Mellon Research Institute.